Rotary pump



July 2, 9 ER 1,719,135

Filed Feb. 10, 1925 mum:

NNNNNN OR July 2, 1929. c RQESSLE'R 1.7l9J35' ROTARY PUMP 'Filed Feb. 10, 1925 2 Sheets-Sheet 2 INVENTOR il LMM C,

/M fl w intention of Patented Jill 2, 1929.

AMANDUS C. ROESSLER, OF CLEVELAND, OHIO, ASSIGN'OR TO THE ROTARY MAOHINE & ENGINEERING COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

ROTARY PUMP.

Application filed February 10, 1923. Serial No. 618,173.

This invention relates to new and useful improvements in pumps and more particularly to the type of pump Comprising a casing having an approximately cylindrical chamber, a rotor or piston cylinder mounted in said casing and in close contact with a portion of the wall of said chamber and a sliding blade carried by said rotor.

One object of my invention is .to provide such a construction in a pump of the "type set forth as will eliminate the back pressure in the pump which retards the operation and causes hammering and undue vibration.

Another object of' my invention is to provide a pump which can be cheaply produced, which will be durable in operation and Very eflicient.

Another object of my invention is the provision of new and improved means for packing the end of the piston blade.

A further object.. of my invention is to provide such an arrangement of parts as will effectually prevent-the fluid, which is being pumped, from being compressed while passing through the pump chamber.

With these objects in View and with the securing other advantages which will hereinafter appear, my invention consists in certain novel features of construction and combination of parts described in the specification, particularly pointed out in the claims and illustrated in the accompanying drawings.

Referring to the accompanying drawings Fig. 1 is a central vertical sectional View of a pump embodying my invention. Fig. 2 is a section on line 2-2, Fig. 1. Figs. 3 and at are similar Views showing slight modifications, and Figxais mdiagrammatic viewillustrating the generation of the curve on which the bore of the cylinder is made.

Again referring to the drawings 3 represents the casing of the pump which is in the form of a cylinder and is mounted on an integrally formed base 4. At each end of the cylinder is formed an annular flange 5.

The end plates or cylinder heads are shown at 6 and 7 and these plates are secured to the cylinder or casing by means of bolts 9 which screw into the flanges 5 on the casing.

On the outer face of each of the cylinder heads is formed a series of radially disposed webs or fins, shown at 11 andl2. These webs both reinforce the heads and also serve to radiate the heat generated through the operation of thepuinp and keep the pump in a suflicientlycool condition to prevent the freezing of the movable parts.

On the inner face of each head or end,

The pump chamber is shown at 19 but the bore is not truly cylindrical, the dotted lines indicating the true circle and the full lines the actual curvature of the bore. The line 22 (which may be termed the median line) divides the pump chamber into sub stantially cylindrical halves and the points where this line cuts, the top and bottom of the pump chamber are concentric, that is to say, they are equal distances from the point where the line XX intersects the line 2-2 and as before stated the dotted line indicates the circle described from this point whereas the actual bore is slightly different upon each side of the median line 2-2.. In this pump chamber thus bored I employ a rotating blade more fully described hereinafter and it is essential that this blade should contact at all times at both of its ends with the walls of the cylinder and as the blade which I propose to use is fixed in its length .it is obvious that this blade constitutes. a

movable chord and as therotor which car-,

ries this blade is mounted eccentrically with reference to the cylinder the proper curvature of the bore can be mathematically obtained from the eccentric relation of the rotor to the bore and the length of the chord. This curve is one form of the Limacon curve and in Fig. 5 I have shown the corresponds to the point of intersection between the lines 2-2 and YY f Fig. 1 and the distance between the lines XX and YY is the amount ofeccentricity between the rotor and the cylinder bore. The circle E is described from a point on. the line 2-2 midway between thelines X-X and Y Yj This circle E is divided into with the radius equal to half of the diameter of the true circle C out the chords as shown at G. When the points marked on the chords are joined together a curve will be produced that will allow a chord having a length equal to the diameter of the true circle C to rotate and slide through the center B and make close contact at both ends with the produced curve at all points. It will also be seen that theoretically the only portions of the curvature that are concentric are at the points where the curve intersects with the line 22. It willthus be readily seen that the relative positions of the rotor and the cylinder bore and the length of the blade are such that by making the cylinder times.

bore upon the developed curve constant contact between the end of the blade and the cylinder wall can be maintained at all times inasmuch as the blade constitutes the movable chord and its center moves around the circle whose diameteri's equal to the eccentricity existing between the rotor or moving member carrying the blade and which will hereinafter be described in detail.

The rotor or piston carrying member 20 is, in general, cylindrical in form and is of such length that it extends from side to'side of the chamber and the ends thereof fit snu ly in the seats 13 and 14 in the cylinder hea s. The rotor is provided at one end with a stud shaft 21 which extends into the blind bearing 15 and at its other end with a driving shaft 22 which extends through the bearing 16 and may be provided with a drum or other means, not shown, for driving the rotor. The general arrangement of the 'rotor with respect to the case is such that the rotor is in close contact with a portion of the wall at the top of the chamber at all In the rotor is formed a slot 25 which passes through the axis of the rotor I and the len h of said slot corresponds to the length of t e pump chamber. In the slot 25 is slidably'mounted a blade 26 the width of which is approximately equal to the length of the pump chamber and the length of said blade is such that both ends of said blade are always in contact with the walls of said "chamber. The blade is preferably 'made of steel and in the end of each blade is formed a semi-circular or concave seat 27.

In each seat 27 is arranged a strip'of packing material 28. In forming this packing thereof and then impart a curvature to the of the chamber.

then set into the seat in the end of the blade so that the base or portion of the strip opposite the truncated face fits into said seat and the side portions project beyond the seat and the face thereof abuts against the wall It will readily be seen that owing to this construction the strip is free to Jrock in its seat as the blade revolves so that the face of the packing strip will at all times conform to and press tightly against the Wall of the pump chamber. F urthermore as the packing rocks one way or the other it will automatically increase the length of the blade and will therefore com .pensate the wear on the wall of the chamber.

being forced through the pump the pressure of the fluid will act against the side of the packingstrip and cramp the strip against its seat greatly increasing the efliciency of the packing.

The intake port 30 is preferably formed at the top of the intake side of the chamber and the outlet port 31 is arranged on the opposite side of the chamber. The relative arrangement of the two ports is such that as one end of the piston blade passes the intake port the other end of the blade will be starting to travel across the outlet port and therefore the outlet port is opened for the escape of [the blade will be forcing fluid through the outlet port all the time it is passing across the outlet port and the rearward end of the blade will at the same time be forcingfluid throu h the outlet port back of the forward end o the blade.

Asbefore mentioned the arrangement is such that a portion of the surface of the rotor for the full length of the rotor is always in gas or liquid tight contact with a portion of the Wall'of the chamber. It therefore follows that as soon as the forward end of the blade asses or clears the outlet port a closed pocket is formed ahead of the blade. When the pump is in operation this pocket will be filled with "gas or liquid and the only chance for it to escape is between the end of the blade and the wall of the chamber. This pocketing of the gas ,or liquid causes a continual pounding of the plump and ultimately results in loosening: e pump from its 100 fluid back of the forward end of the blade mounting and injury to the driving mech-- anism; To obviate this difiiculty I form an open duct or groove 35 in the top Wall of the pump chamber at the outlet side of said chamber. This groove extends longitudinally of the chamber and in close proximity to the line of contact between the rotor and the Wall of the chamber. A subsidiary outlet or vent passageway 36 is formed in the wall of the pump chamber and one end of this passageway communicates with the duct 35 and the other end communicates with the outlet passage from the outlet port 31. The fluid which would otherwise be trapped finds a ready means of escape by the way of the duct and the vent passageway 36, making possible a perfect delivery of the whole contents of the pump. Also all extra strain placed upon the pump on account of the pocketing of the fluid is entirely eliminated together with the hammering caused thereby,

rendering the operation of the pump noiseless and greatly increasing the durability of the pump.

In Figs. 3 and 4 I have shown views substantially the same as Figs. 1 and 2 and in which there is a slight addition as in order to prevent pressure being built up in the dead end of the end plate 6 which would produce end thrust upon the .rotor, I provide a suitable passage 37 communicating between the dead end of end plate and the intake portionof the pump body and in this manner pressure equilibrium is maintained and all end thrust prevented. I' also provide a suitable passage 38 leading from the gland box 39 to the intake portion of the pump, the object of which is to prevent any fluid seeping from the gland, by intercepting the .fiuid that may work past the first few turns of the gland packing, and by the action of the pump sucking it back to the inlet of the pump, leakage at the gland is entirely prevented.

What I claim is 1. In combination with a pump casing having a chamber with intakev and outlet .ports on opposite sides thereof, a piston journaled in said chamber having fluid-tight contact with the walls thereof, and having a supporting shaft provided with a blind bearing in one of the side walls of said chamber, said-casing having a groove ex- 1 tending from the dead end of said blind bearing to the intake side of said pump caswhereby axial pressure equilibrium is ing, maintained.

2. The combination with a pump casing having a chamber with the intake and outlet ports arranged on opposite sides thereof,

end of said blind bearing to the intake side of pump and a second passage extending from the gland box to the intake side of pump, whereby pressure equilibrium is maintained in the opposite ends of said bearings.

3. The combination with a pump casing having a chamber with theintake and outlet ports arranged upon opposite sides of such chamber, a piston cylinder rotatably mounted on a shaft journaled in said chamber and in contact with the end walls of said chamber, a blind bearing for said shaft in'one of the side walls of said chamber and a sliding blade mounted in said piston cylinder so that the end of said blade will fit the side wall of said chamber at-all points in the rotation of said blade, said pump casing being provided with a passage extending from the dead end ofsaid blind bearing to the intake side of said pump, whereby axial equilibrium is maintained.

In testimony whereof, I hereunto aflix my signature. 4

AMANDUS o. RoEss 'ER. 

